This application claims priority of International application No. PCT/FR99/01404, dated Jun. 14, 1999, which in turn claims priority of French application No. 98/08536, filed Jul. 3, 1998.
The present invention relates to the determining of the tenderness of meat, in particular of beef, on the transformation site by means of biological and/or physico-chemical data and optical measurements in the visible and near infrared range.
Among the numerous factors of quality of meat, such as juiciness, tenderness, colour, or flavour, tenderness is considered as the factor of quality which gives the most satisfaction to the consumer.
It is therefore economically important for meat producers to be able to determine the tenderness of a meat rapidly and as early as possible in the process of transforming the meat in the industrial environment (abattoir). Moreover, and above all, this determination must be reliable in order to guarantee the quality up to the stage of consumption.
A large number of industrial methods of determining the quality of meat are already known, in particular of the non-destructive type (i.e. without cutting away samples).
In the French Patent 1 550 169, a probe determines the colours of meat by means of a light transmitted by a piece of meat subjected to observation. The instrument comprises an emission branch and a reception branch intended to be inserted into the meat. A lamp gives out a light by the emission branch located opposite the reception branch. Such a document does not specify the wavelengths of the light used. Moreover, only the colours of the meat are determined, which is insufficient in order to determine the tenderness of the meat with a satisfactory degree of reliability.
In the publication EP-A-0402877, a probe is inserted into a piece of meat in order to determine its quality. The technique used is to measure the intensity of light reflected (reflectance) in the visible or near infrared spectrum. With such a probe it is only possible to estimate the concentrations of one or more components of the meat, which is not sufficient to determine the tenderness of the meat with a satisfactory degree of reliability.
The object of the present invention is to improve the reliability of the prior techniques for determining the quality and in particular to determine the tenderness on the transformation site.
The invention relates to a method of determining the quality of meat, in particular beef, which can be used on a production line on the transformation site.
According to a general definition of the invention, the method comprises the following stages:
a) to collect, on the transformation site, data relating to parameters belonging to the group formed by the breed, age and category of animal as well as biological and/or physico-chemical parameters of the animal carcass belonging to the group formed by the weight, conformation, fleshing, the pH value and the colour of the carcass, as well as the thickness of the hide,
b) to obtain at least one optical spectrum of the meat corresponding to wavelengths belonging to a spectral field ranging from visible light to near infrared, and
c) to combine the data obtained at stages a) and b) with a view to determining the tenderness of the meat according to a predetermined equation drawn up relative to a predetermined scale of reference of tenderness.
The Applicants have observed that certain parameters of the animal and its carcass, such as breed, age and type of animal as well as weight, conformation, fleshing, the pH value, the colour of the carcass and the thickness of the hide etc. are data which are correlated with tenderness.
However, until now no model for determining tenderness has used these data directly, probably due to ignorance or a lack of interest therein on the part of scientists.
In spite of this prejudice, the Applicants use them in order to combine them furthermore with optical measurements with a view to a more reliable determination of the tenderness of meat on the transformation site.
The data (breed, age, category of animal, weight, conformation, fleshing, pH value, carcass colour, thickness of hide etc.) are hereinafter referred to as xe2x80x9cexpert dataxe2x80x9d, because they derive from an in-depth knowledge of the animal and the features which influence tenderness.
The method according to the invention makes it possible to supply an objective, nondestructive determination of the tenderness of meat which can be carried out on a production line on the transformation site in an industrial environment without having recourse to sophisticated, expensive devices.
Moreover, the results of determination according to the invention are sufficiently reliable to be able to guarantee tenderness with a high level of probability at the time when the meat leaves the transformation site in an industrial environment.
In practice, the stage b) is effected in reflection and/or emission mode.
In transmission mode, stage b) comprises the following stages:
b 1) to provide a probe comprising an emission branch and a reception branch, spaced apart by a predetermined distance;
b 2) to insert the emission and reception branches into a selected piece of meat to a selected depth;
b 3) to illuminate the piece of meat by means of the emission branch thus inserted into the piece of meat by wide-band light radiation at a frequency ranging from visible light to near infrared;
b 4) to receive the light transmitted by the piece of meat by means of the receiving branch thus inserted into the piece of meat; and
b 5) to record a transmission spectrum of the piece of meat ranging from visible light to at least near infrared.
In reflection mode, the probe comprises a single branch for emission and reception of the incident light and reflected light respectively.
In practice, the determination equation is drawn up over a significant series of different pieces of meat of different animals for each of which spectral data and non-spectral data are obtained according to stages a) and b) and compared to a scale of reference drawn up by means of sensorial data and/or data of the shearing force, and/or of the force of compression measured over the significant series of different pieces of meat.
Preferably, determination is carried out by a multidimensional statistical method such as the method of smallest partial squares, in order to obtain a mathematical determination model intended to be used on each piece of meat whose tenderness is to be determined.
According to another feature of the method, stage b) is effected on the carcass, quarters, muscles or steaks.
A further object of the present invention is a device for determining the quality of meat, in particular beef, on the transformation site.
According to a general definition of the device according to the invention, the device comprises:
means of collecting on the transformation site data relating to parameters belonging to the group formed by the breed, age and category of animal as well as biological and/or physicochemical parameters of the animal carcass belonging to the group formed by the weight, conformation, fleshing, the pH value and the colour of the carcass, as well as the thickness of the hide,
means of obtaining at least one optical spectrum of the meat corresponding to wavelengths belonging to a spectral field ranging from visible light to near infrared, and
processing means for combining the data obtained at stages a) and b) with a view to determining the tenderness of the meat according to a predetermined equation relative to a predetermined scale of reference of tenderness.